The technology relates to a charging device for discharging in an electrophotographic image forming process and to an image forming apparatus provided with the charging device.
A noncontact charging device adapted for use in an electrophotographic image forming apparatus includes an electrode. Application of high voltage to the electrode causes the electrode to discharge toward a photoreceptor. A needle electrode commonly used has the advantage of generating only a small amount of ozone on application of high voltage thereto.
However, a portion of the needle electrode that generates a high-voltage electric field attracts ambient dust.
Large amounts of dust on the electrode prevent proper discharge thereof.
JP H11-338265A discloses a charging device that includes a needle electrode and a pair of pads. The electrode has a plurality of arrayed needles. The pads are movably supported on both sides of the needle array of the electrode. Movement of the pads along the needle array brings the pads into contact with the needles in order so as to remove dust from the needles.
In the prior art device, a cleaning member including the pads are manually moved. Thus, the electrode sometimes cannot be cleaned at an appropriate time according to the amount of dust thereon.
A feature is to provide a charging device capable of reciprocating a cleaning member precisely and accurately between both ends of a needle electrode with a simple control and configuration irrespective of the amount of dust on the electrode, and an image forming apparatus provided with the charging device.